Twister cap



TwIsTER cAP f- June 9, 1942.

' rotation.

the bobbin is full, the

around the lower end of the cap, being in con- Patented June 9, 1942Ivern J. Jordan,

mann, Lakewood,

and Alden H.

OFFICE Richard F. Berg- Burkholder,

Cleveland, Ohio, assignors to Industrial Rayon Corporation, DelawareCleveland, Ohio, a corporationfof Application June 3, 1941, Serial No.396,420

This invention relates to caps for use in captwisting apparatus of thekind employed in twisting thread or the like.

In the operation of cap-twisting apparatus, the thread or the liketo betwisted is drawn from a suitable source, through a` thread guidedislower edge of thel cap, the outside of the cap in what is known as aTwist is imparted to the thread by thread as it leaves the source.

When the twisting operation is rst begun; i. e.. with the bobbin empty,the thread travels about Y ,the `cap in a path bowed laterally outwardfrom the side of the cap but otherwise extending sub- As the bobbiniills, the threadpath becomes progressively more bowed, particularly inthe vitime, the path of the thread between the thread the lower edge ofthe cap assumes an increasingly pronounced spiral form imposed byrelative lateral displacement of the upper and lower portions of thethread path. By the time thread is in eiect wrapped tact with the sideof the capforseveral inches above the edge thereof. A

In the meanwhile, the angle between the length of thread passingfrom theedge of themap to the surface of the bobbin and an imaginary tangent tothe cap at the point where the thread passes under the edge of the capgressively smaller. As the angle is decreased, the component of forceoperating to cause the the thread travels about upper edgev of the cap.At the same becomes pro- 1a claims. (cl. 57-127) thread onto the bobbinmers dimcumyy @mybeside and lower edge of the cap isincre'ased .to adegree as to cause a drag in the thread itself.

y Inasmuch as vconsiderable friction is developed as the thread movesaround the cumbersome and 4costly to manufacture. They do, of` course,have the importantadvantage lof being rigid in construction. f v

Heretofore, `most twisting operations have been over.v It is worn awayeven more quickly when,

cap are of great importance. In apparatus of the kind f disclosed inPatent 2,225,642, as many as 10,000

may be employed simul eously in a single between the thread and the'cap, the partv or v often the case, it is a pigmented thread thatvcap-twisting units V phere.

2 l plant. When it is desired to remove a completely fllled bobbin fromone of these units, the opf era'tor grasps the top of the twister capwith one hand, removing it from the spindle assembly by lifting itupward. With the other hand he grasps the top of the filled bobbin,removes it from the spindle assembly, places it in a rack, and replacesit with an empty bobbin. This done, he replacethe twister cap. Since theoperator continues to hold the twister cap in the same hand throughoutthese operations, it is desirable to employ a cap that islight inweight; however, it

is no less important that the: cap berigid.

In order to keep down the weight of the cap, it should obviously be assmall as possible. Where, however, the amount of thread being twisted inone length is an important factor, it is necessary to wind a package aslarge as possible at the highest practicable speed. In suchcircumstances, a two-fold desideratum is presented; viz., keeping thetwister cap as small as possible while winding the largest possiblethread package. Y

The necessary combination of rigidity, light weight and satisfactorywearing qualities is to be found in the capof the present invention,which cap is highly resistant to corrosion, strongly con- `structed, yetvery light -in weight. The surfaces of the cap in contact with thethread are so constructed as to reduce toa minimum the fricgtional dragupon a the a yarn passingfthereover. fThe cap as a whole, including theparts thereof coming into contact with thread, is of materials which areparticularly adapted to use` in captwisting apparatus operated in ahumid atmos- Without intending to limit the invention thereto, aparticularly satisfactory embodiment of the invention is4 illustrated inthe accompanying drawing. Figure 1 is a `sectional elevation of aportion of a cap-twisting apparatus showing the twister cap of thepresent invention, the bobbin,

Yand the parts 'of `the spindle assembly normally associated therewith.Figure 2 represents a side elevation of the apparatus from line 2-2 ofFigure l. Figure 3 is a portion of the sectional elevation of Figure1-.on a greatly enlarged scale, the portion being from the lower edge ofthe cap.

'As shown in Figure 1, the apparatus as a whole comprises a stationaryspindle shaft I surrounded by a sleeve, 2 capable of reciprocatinglengthwise of spindle shaft I, the sleeve being shown in its uppermostposition. A collar 3 fixed to sleeve 2 serves to carry rotary whorl andbobbin support 5. Bobbin 6 is mounted on support 5, rotational movementfrom a belt (not shown) being transmitted thereto by means of Iwhorl 4and support 5. Thus while spindle shaft I remains stationary,` sleeve 2can reciprocate vertically and whorl 4, support 5 and bobbin 6 canrotate about sleeve 2 as it reciprocates.

Cap 1` is mounted in the usual way on the upper end of spindle shaft Iin such manner that the movable parts ofthe spindle assembly canreciprocate and rotate within the cap.

The cap itselfk includes a boss 8 to which is attached a dome 9, suchdome serving to support skirt I0. ,Ring II is attached to the lower lendof skirt I0 to guide the thread A in the manner hereinafter explained asit is being wound in package form on bobbin 6. Boss 8 has formed thereina ltapered bore I6 which seats cap 1 upon tapered surface I1 of spindleshaft I tohold the cap in place, the weight of the cap being sufcienttohold it on the` spindle dome 9. Shoulder 2I on dome 9 and shoulder 22 onskirt Ill also assist in holding the, partsof the cap in assembledrelation, particularly if a cementitious material is employed to bindthe parts together. Such ya construction makes it possible to assembleand disassemble the cap with ease and rapidity.

4Skirt III is of laminated construction, being made of a syntheticplastic such as Bakelite whichl is reinforced with sheets offlber,'cloth,

paper or other suitable material. One laminated plastic of this type issold under the trade-name Micarta. Such materials not only are resistantto corrosive fumes but take on a high polish which is maintained duringand in some cases even improved with use. Since, according to thepresent invention, no thread comes into contact with boss 9 or dome 9,both of the latterl may be painted with lacquer or otherwise coated toprevent corrosion.

Ring II is fitted on the end of skirt I0, shoule der 29 on skirt IIIserving to locate ring II on said skirt; preferably, ring II is cementedto the ,skirt I0.

`inasmuch as the greatest wear takes place where the thread passesaround the edge of ring II, such ring is preferably made of a'high gradestainless steel such as the hardened nickel-free chrome alloy steelknown in the trade and under SAE specifications as stainless steel alloy420 or Carpenter 2 vstainless steel. This alloy,

`whichis of the same quality as high grade cutlery steel, is not onlycapable of being hardened but of taking on a high polish. An analysis ofthis alloy shows that it contains about .30% carbon and about 13.00%chromium. In lieu thereof, various other alloys which are equally ormore resistant to abrasion may be employed.

As appears from Figure 3, ring I I is beveled to provide a definiterelationship between outer surface 24 and inner surface 25, arc 25serving to join the two surfaces. Preferably inner surface 25 is at anangle of approximately 30 to outer surface 2B. Arc 2B is tangent to bothouter surface 24 and inner surface 25. The radius'of arc 26 should beless than .01 inch whenthe twister cap on which it is mounted isapproximately ten Y inches long and five inches in diameter and thecollecting bobbin on which the thread is being wound is approximately 2%inches in diameter. This radius serves adequately for thread having adenier as low as or lower than one hundred.

The radius of the arc joining the beveled inner surface 25 of ring IIwith thev outer surface 2l thereof is determinative of the path of thethread in the balloon, this following from the fact that, by decreasingthe tension in the thread, the reduced radius allows the thread to bebowed farther outward from the cap.

If, because of rapid wear, the radius changes within a relatively shorttime, the critical character of such radius becomes even more critical.With a hardened steel alloy of high quality, it is possible to machinethe rings down to a tolerstainless steel variety may be ever featuresoi' Lto which they are subjected.

3 what is calmed is:

d l. A twister cap comprising ametal dome; a

when thread of o denier, 4o filaments, 1s

being twisted, the preferred radius of the arc 26 is approximately .005inch, plus or minus .002 inch. The diameter of the empty bobbin shouldin such case be approximately 2% inches. Under these conditions, theballoon will completely miss the upper portion of twister cap l from thevery start of the winding operation, being far enough from the upperedge of the cap to be free from contact therewith even in the twistingof thread of low denier. This is due to the relatively low tension inthe thread between the edge of the ring and the surface of thecollecting bobbin, as well as between the lower edge oi' the cap and thethread guide above the cap.

At the same time, the tension in the thread between the lower edge ofthe cap and the periphery of the bobbin is substantially reduced.

The apparatus of the invention is particularly suitable for use in highspeed winding operations. For instance, when the thread to be twistedpasses from the source at a linear speed of approximately 76 meters perminute, the bobbin upon which the thread is collected is rotatedat anangular velocity of approximately 8,000 revolutions per minute. Thisimpartsa twist of approximately two and one-half turns per inch to thethread. Operations at such high speed necessitate apparatus which isdurable and yet efiicient in operation: these requirements the apparatusof the present invention amply satises.

The twister cap illustrated in the drawing represents the preferredembodiment of the invention as it is employed in the twisting ofpigmented thread at comparatively high speeds. However, modications asto construction and use of materials may be made without departing fromthe spirit of the invention. Skirts made according to the invention maybe constructed of plastic material which has sumcient strength in and ofitself without laminae incorporated therein; also, the ring may be madeof other types of wear-resistant material than that described herein.For instance, if the apparatus is not operated in an atmosphere of awear-resistant metal not necessarily of the employed. It is intendedthat the patent shall cover, by suitable expression in the'appendedclaims, whatinvention.

high humidity, etc..

patentable novelty reside in the on-metallic skirt attached to saiddome; and. attached to the lower end of said skirt, a beveled ring ofwear-resistant material, the inner and outer surfaces of said ring beingjoined by an arc tangent to both of said surfaces.

2. A twister cap comprising a metal dome, said domeincluding a mountingboss; a substantially4 cylindrical non-metallic skirt attached to saiddome; one or mcreannular ridges adjacent the lower edge of said dome;one or more annular grooves adjacent the upper edge of said skirt. saidgrooves cooperatingwith said ridges to hold said dome and said skirt inassembled relation; and a wear-resistant ring mounted at the lower edgeof said skirt.

3. A twister cap comprising a. metal dome; a non-metallic skirt attachedto said dome; and a hardened metal ring mounted at the lower edge ofsaid skirt.

4. A twister cap comprising a metal dome; a substantially cylindricalmolded plastic skirt; and, mounted at the lower end of said skirt, ahardened metal ring. A

5. A twister caplof the character described in claim 4 wherein the skirtis made of plastic material having a non-metallic reinforcing materialincorporated therein.

6. A twister cap of the character described in claim 4 wherein the ringis made of a hardened steel alloy. A l

7. A ring for twister caps comprising a bevv eledl annular ring, theinner and outer surfaces of said ring being joined by an arc having aradius not greater than .01 inc 8. A ring of the character described inclaim 7 which ring is made of a stainless steel alloy..` a

9. A ring of the character described in claim 'I in which the inner andouter surfaces thereof are inclined to each other at an angle ofapproximately 30.

l0. A ring of the character described in claim 7 in which vthe arc istangent to at least one of said surfaces.

il. A ring of the character described in claim 7 in which the radius ofthe arc is from .003 to .Lai/EBN J. JORDAN.

1:1 F. BERGMANN. 1 H. BURKHOLDER.

hardened, nickel-free.

